设计一个学生类student,包括姓名和三门课程成绩，利用重载运算符将所有学生的成绩相加放在一个对象中，再对该对象求各门课程的平均分, 并编写完整的程序进-Design a student class student, including name and three course score, the use of overloaded operators will add the results of all students placed in an object, and then demand that the object of the average of all courses and the preparation of a complete program into the